Railway traffic controlling apparatus



June 6, 1944. 5 YOUNG RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 5, 1943 2 Sheets-Sheet 1.

I l I a fig h.

INVENTOR 7 J. Young BY I Q' Q Hrr ATTORNEY June 6, 1944. i .H. s. YOUNG I 2,350,705

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 5, 1943 2 Sheets-Sheet? I m v Jim IO [I a1 [o lil INVENTOR Him ATTORNEY Patented June 6, 1944 V UNITED STATES PATENT OFFICE RAILWAY TRAFFIo CONTROLLING APPARATUS Application January 5, 1943, Serial No. 471,350

12 Claims.

My invention relates to railway traffic controlling apparatus, and has particular reference to the organization of such apparatus into novel and improved signal systems of the class incorporating locking means of the type arranged to prevent operation of an interlocking function such as a track switch unless the associated home signal is displaying stop and all distant signals leading up to the interlocking are displaying the proper restrictive indications.

It has been proposed heretofore to govern a distant signal by means of a polarized relay energized over a track or line circuit controlled by the home signal and by trafiic in the approach section governed by the distant signal. The arrangement is such that when the approach section is occupied, the polarized relay is deenergized and causes the distant signal to display stop; when the home signal is displaying stop and the approach section is unoccupied, the polarized relay is energized by current of one relative polarity and operates its polar armature to its caution position to cause the distant signal to display caution; and when the home signal is cleared and the approach section is unoccupied, the polarized relay is energized by current of the opposite relative polarity and operates its polar armature to its clear position to cause the distant signal to display its clear aspect.

In such systems it is customary to provide means for locking the'control lever of the home signal and to release the looking on that lever and hence the interlocking between that lever and the lever or levers controlling switches located in advance of the home signaLonly in the event that the home signal is displaying stop and the distant signals leading up to the interlocking are displaying the proper restrictive indications. To effect this, the lock releasing circuits are arranged normally to include back contacts of the 40 signal control relays of the home signal and a polar contact of the polarized distant signal control relay closed in the caution position of the polar armature of that relay. In addition, an

alternate circuit usually is provided, wherein a result in a loss of check on the distant signal since the locking is released over 'a back contact of the distant signal control relay and hence it does not check the position of thepolar armature of that relay. If the polar armature of the relay should stick in its clear position it is thuspossible that a clear indication might be displayed by the distant signal with the home signal displaying stop and the interlocking between the home signal lever and the switch lever released. The display of the clear aspect by the distant signal under such conditions is of course improper and is termed a false clear signal indication.

In view of the foregoing and other important. considerations, it is an object-of ,my present invention to provide novel and improved means for controlling the locking of the control lever of a home signal at an interlocking plant.

Another object is the provision of novel and improved means for checking the display of a caution indication bya distant signal at anointerlocking plant.

An additional objectis the provision of novel and improved means for controlling a distant signal at an interlocking plant to cause that signal to display its most restrictive aspect should the polarized relay controlling that :signal fail to operate properly.

A further object is the provision of novel and improved means for preventing a. .false clear aspect from being displayed by a distant signal in an interlocking plant.

In practicing the invention, the above-mentioned and other important objects and characteristic features of my invention which will become readily apparent f-rom the following description are attained by controlling a distant signal through the medium of a polarized cont-rel relay and .a stick relay. The stick relay is arranged to be normally energized over a stick aircuit controlled by .trafiic in the section governed by the distant signal, and is provided with a pickup circuit completed over a polar contact closed in the caution position of the polar armature of the polarized control relay. The stick relay when picked up conditionsth'e distant signal to display a caution ora clear aspect according as the polar armature of the polarized control relay is its caution or clear position respectively, and when the stick relay is released the signal is caused to display its stop aspect. The invention provides means controlled by the stick relay eifective to cause the polarized relay to operate its polar to vacate the approach track section, but it may armature to its caution position when the section governed by the signal becomes occupied, and it also contemplates using only the caution position polar contacts of the polarized relay in the lock releasing circuit for the lever lock provided on the control lever of the associated home signal, thereby checking the position of the polar armature of the polarized relay each time that the locking is released.

Other important features of my invention reside in the apparatus employed and the specific arrangement thereof, as will be made clear in the following description. V

I shall describe several forms of apparatus embodying my invention and shall thenpoint out the novel features thereof in claims.

In the accompanying drawings, Fig. .1 .is a diagrammatic view illustrating one form of apparatus embodying my invention. Figs. 1a, 2 and 3 are diagrammatic views each showing modifications. of the apparatus represented in Fig. 1 and embodying my invention. In each of the several views, similar reference characters have been employed to designate corresponding parts.

Referring to Fig, l, the reference character I and la designate the track rails of a stretch of railway track divided by insulated joints 2 into a track section 3T over which traffic normally operates in the direction indicated by an arrow or from right to left as viewed in the drawings. Trafiic operating'in the normal direction in section ST is governed by a signal 3S located adjacent to the entrance or right-hand end of the section, while trafiic operating in the normal direction of traffic in the stretch in advance of section 3T is governed by a signal IS located adjacent to the exit or left-hand end of the section. Signal IS is a home signal of an interlocking plant and comprises an upper signal unit a for governing main line movements and a lower signal unit I) for governing diverging movements such as over a track switch IW shown in the drawings.

The reference character AI-IR. designates a signal control relay for controlling unit a of signal IS, and the reference character BI-lIR. designates a signal control relay for controlling unit I) of signal IS. The specific control circuits of the two units may be of the usual type and hence have been indicated only conventionally in the drawings for the sake of simplicity, but it is to be understood, of course, that'each signal unit will be cleared only when its associated signal control relay is energized and will be set to stop when its associated signal control relay is deenergized.

The reference character ISL designates a signal control lever incorporated into an interlocking machine and provided with a plurality of contacts including contacts 5 and 6 selectively closed in accordance with the position of the lever for controlling signal control relays AHR and BI-IR. Thespecific control circuits of these signal control relays may be of the usual type and hence have been indicated in a conventional manner in the drawings for the sake of simplicity, it being switch is reand unit I) for control when the versed for a diverging movement.

Lever ISL normally occupies a normal position N, and is movable through an intermediate position B to a control position L wherein contacts 5 and 6 are closed to prepare the control circuits of relays AHR and BHR. LeverISL has operatively associated therewith a back lock comprising a lock magnet LM, a locking dog In, and a lock segment I I operatively connected with lever ISL. When magnet LM is deenergized, dog Ill rests upon segment II which is provided with a shoulder engaged by the dog at position B of the lever and disposed so as to prevent movement of lever ISL from its control position L to its normal position N past position B unless the magnet is energized to attract dog I0 out of engagement with segment II. The magnet LM is provided with an energizing or back lock release circuit which will be pointed out in the following description.

The reference character IWL designates another control lever incorporated into the interlocking machine for controlling another function, such as switch IW. Lever IWL has two extreme positions N and R and is interlocked as by suitable mechanical interlocking, indicated conventionally in the drawings, with signal lever ISL in such a manner that lever IWL may be operated from either extreme position N or R to the other only if lever ISL occupies its normal position N.

The other signal 38 is a distant signal leading up to the home signal IS. Signal 3S is controlled by a polarized relay PR and a stick relay, designated by the reference character SR in Fig. l. The polarized relay PR may be controlled over a polarized line circuit as shown in Fig. 1, or a polarized track circuit as shown in Fig. 2. In either case, the polarized circuit of relay PR is governed by the control means of signal IS and by traflic conditions in section 3T. Thus, for example, relay PR in Fig. 1 may be energized by current of what I shall term normal polarity supplied over a line circuit extending from one terminal X of a suitable source of current, such as a battery not shown, through back contact I4 of relay AHR, front contact I5 of relay 3TR, the winding of relay PR, front contact I6 of relay 3TR and back contact I! of relay AHR to the noted, however, that the circuits will be con- I trol when the switch is in its normal position other terminal C of the same source of current. When relay AHR is picked up, its front contacts I8 and I9 will be closed and the polarity of current supplied to relay PR will be reversed, as is obvious from an inspection of the drawings, hence it follows that relay PR is controlled in part at least by signal control relay AHR, employed in the control of signal IS, It is of course apparent that when section ST is occupied and relay 3TB is released, the energizing circuit just traced for relay PR will be open at front contacts I5 and I6 of relay 3TH, hence it follows that this circuit is likewise controlled by trafiic conditions in section 3T as reflected by relay 3TH. When the back contacts 20 and 2I of relay 3TR close, an alternate circuit Presently to be traced in detail i momentarily completed for a purpose to be made clear in the following description. Relay PR is arranged to operate itspolar aramture to its caution or left-hand position, as viewed in the drawings, to close its caution position polar contacts when energized by current of normal polarity, and shifts its polar armature to its clear or right-hand position to close its clear position polar contacts when energized by current of reverse polarity. I

relay SR to terminal C. Relay SR is provided,

with a pick-up circuit completed only when relay PR' is energized by current of normal polarity and its polar armature properly operates to its caution or left-hand position in response to energizing current of normal polarity supplied to the relay. Ifhis pick-up circuit of relay SR is cornpleted in the caution position of the armature of relay PR because its polar contact 25 is then closed and completes an obvious circuit path around front contact 24 of relay SR in the stick circuit of relay SR just traced.

Relay SR is slow in releasing so that it will bridge the open circuit interval of the front neutral contacts of relay PR when the polarity of current supplied to relay PR is reversed. In addition, the slow releasing features of relay SR maintain its front contact 23 closed fora short interval after relay 3TB, releases to interrupt the circuit of relay SR, and during this short interval relay PR will become energized by current of normal polarity supplied over a circuit extending from terminal K through front contact 28 of relay SR, back contact 29 of relay 3TB, the winding of relay PR and backcontact 2| of relay 3TB to terminal C. Relay PR accordingly is caused to shift its polar armature to its caution position each time section 3T becomes occupied and relay 3TB releases to deenergize relay SR.

Relays SR and PR jointly control signal 38 in such a manner that signal 38 displays its stop aspect when relay SR is released and back contact 29 is closed to energize lamp R of signal 33 over an obvious circuit; signal displays its caution aspect when relay SR is picked up and the polar armature of relay PR occupies its caution position to close polar contact 31 and complete a circuit extending from terminal K through front contact 30 of relay SR, polar contact 35 of relay PR and the filament of lamp Y of signal 38 to terminal C; and the signal is caused to display its clear aspect when relay SR is picked up and the polar armature of relay PR occupies its clear position to close polar contact 32 so that lamp G of signal 3S becomes energized over a circuit which passes from terminal X through front contact 33 of relay SR, polar contact 32 of relay PR and the filament of lamp G of signal as to terminal C.

The previously mentioned lock release circuit for lock magnet LM may be completed only if the polar armature of relay PR is in its caution position to close polar contact 33 and signal control relays ,AHR and BER are released, thereby providing a check upon both the distant and home signals. The lock release circuit may be traced from terminal X through polar contact 33 of relay PR, hack contact 35 of relay AHR, back contact 35 of relay BER, contact 36 f lever iSL Closed in the intermediate or B position of the lever and the winding of lock magnet LM to terminal C. It will be noted that this circuit contains no alternate circuit path completed through a back neutral contact of the polarized relay PR and hence this circuit differs to that extent from the usual back lock release circuits customarily employed in interlocking systems.

In the normal condition of the apparatus as represented in Fig. l, signal lever ESL is in its normal position so that control relays AHR and BHR are released to cause the associated units a and b of signal is to display stop; section 3T is unoccupied and relay PR is energized by current of normal polarity supplied over its previously traced circuit including back contacts M and I! of relay AI-IR and front contacts l5 and it of relay 3TH; relay SR is held energized over both its previously traced stick and pick-up circuits; and lamp Y of signal 38 is energized over its previously traced circuit so that signal 3S displays its caution aspect. In this condition of the apparatus, lever lWL is unlocked so that the operator may operate switch lW to any desired position. 1

If, now, with switch [W occupying its normal position, lever ISL is moved to its control posi tion, relay AHR will be selected for energization by contact I of switch lW and that relay will pick up to cause unit a of signal is to display its clear aspect authorizing a main line movement over the switch. Relay AHR will also close its front contacts 58 and 9 to reverse the polarity of current energizing relay PR, whereupon that relay will shift its polar armature to its clear position wherein lamp G of signal 38 will become energized over a circuit including front contact 33 of relay SR and polar contact 32 of relay PR.

Relay PR will of course open its front contact 22 when the direction of current in its winding is being reversed, but relay SR will not release at this time because of its slow release features, so that when front contact 22, of relay PR g in closes, relay SR is held energized over its stick circuit.

When a train enters section 3T, relay 3TB is shunted and eleases to open the previously traced reverse circuit of relay PR and the stick circuit of relay SR. During the slow release in terval of relay SR, its front contact 28 is held closed to complete momentarily the previously mentioned alternate circuit of relay PR, whereupon that relay becomes energized by current of normal polarity and shifts its polar armature back to its caution position. Also, when relay SR releases at the end of its slow release period, its back contact 29 closes to cause signal 38 to display its stop aspect. Then, when the train passes signal IS and relay lTRreleases todeenergize relay AHR and cause signal unit a of,

signal is to display stop, the operator will be enabled to restore lever ISL to its full normal position N since the back lock release circuit will be completed at contact 36 closed at the intermediate position B of lever ISL. The energizaticn of magnet LlVI assures the operator that all units of signal 13 display stop and that the polar armature of the polarized control relay PR governing signal 33- is positioned in its caution position.

After the train vacates section 3T, relay 3TB will pick up and its front contacts I5 and [6 will close to complete the previously traced line circuit including backcontacts I 4 and H of relay AHR and over which current of normal polarity is supplied to relay PR. As a result, relay PR Will pick up and close its front contact 22 to completerthe previously traced pick-up circuit of relay SR, whereupon that relay in turn picks up to close its stick circuit at front contact 24 and the caution circuit of signal 3S at front contact 30.

From the foregoing description, it is readily apparent ha the appara us is ran d o ieleast the back looking on signal lever ISL after a train passes signal IS provided that the polar armature of relay PR has properly operated to its caution position when section 3T becomes occupied. This provides a release of the back look-- ing similar to that heretofore effected over a back contact of the polarized control relay PR of the distant signal, that is, the locking is released in both cases with relay PR deenergized. In addition, however, the apparatus embodying the present invention is arranged to check the position of the polarized armature of relay PR at all times in the back lock release circuit. In other words, since the locking is released only over a polar contact closed in the caution position of the polar armature of the polarized relay, the release of the back locking always signifies that the polar armature of the polarized relay has operated properly and is in the caution position wherein signal 38 will be caused to display its proper caution aspect when its section becomes vacant. v

If the polar armature of relay PR should stick in its clear position and the relay should fail to operate the armature from its clear toits caution position when section 3T is entered, the apparatus functions to prevent a release of the back locking and a display of a false clear aspect by the distant signal 38. That is to say, if the polar armature of relay PR should stick in its clear position, then after the train enters section 3T and subsequently passes signal IS, the back lock release circuit will be held open at polar contact 33 of relay PR if the operator attempts to restore lever ISL to its normal position. Lever ISL accordingly will be locked out of it normal position and lever IWL as a result will be maintained locked in its last operated position by the mechanical interlocking between it and lever ISL. This sticking of the polar armature of relay PR would not be detected at this time by systems incorporating the usual back lock release circuit because in such systems the release is usually effected by the by-passcircuit completed through a back neutral contact of the polarized relay connected around the polar contact of the relay.

As stated previously, when section ST is vacated by the train and relay 3TR picks up, relay PR will be energized by current of normal polarity and it in turn will ick up. If, as has been assumed, the polar armature of relay PR is stuck in its clear position, the position of the armature will not be in agreement with the polarity of current supplied to the relay, and but for the provision of stick relay SR, signal 3S might be caused to display a false clear aspect instead of the proper caution aspect. That is to say, with the polar armature of relay PR stuck in its clear position and the neutral front contacts of the relay closed due to the energization of the relay by current of normal polarity, a circuit condition is established which in normal practice (where relay SR is not employed) might cause signal 3S to display a clear aspect. This aspect of course would be improper under the conditions where the home signal is displaying stop since under such conditions the most favorable aspect that signal 33 should display would be'a caution indication.

The display of a false clear aspect is prevented by the apparatus of Fig. 1 since under the conditions assumed wherein relay PR is energized by current of normal polarityto close its front contacts but its polar armature'is stuck in theclear position, relay- SR will not be picked up becauseits pick-up'circuit will be open at polar contact 25 of relay PR. Relay SR accordingly will remain released and will cause signal 38 to display its stop aspect. It follows, therefore, that the apparatus of Fig. 1 is arranged to prevent the display of a false clear signal and the release of the back looking on signal lever ISL if the control relay PR of the distant signal 38' fails to operate its polar armature in the proper manner.

A modified arrangement of the apparatus of Fig. 1 is shown in Fig. 1a, wherein relay SRI is energized over an obvious circuit including front contact 22 of relay PR and front contact 23 of relay 3TR. In such an arrangement, relay SRI is picked up whenever relays PR and 3TR are picked up, hence no protection is provided to prevent signal 38 from displaying a false-clear indication should the polar armature of relay PR stick in its clear position. The arrangement does, however, check the position of the polar armature of relay PR at all times in the back lock release circuit so that any failure of the polar armature of relay PR to operate properly will result in holding open the back lock release circuit at polar contact 33 of relay PR. It follows a failure of the polar armature of relay PR to operate properly will prevent operation of control lever ISL into its normal position N and this in turn will indicate to the operator that the polarized relay has failed to operate its polar armature in the proper manner.

In Fig. 2, another alternate circuit arrangement of the apparatu of Fig. 1 is represented wherein a stick track relay TSR and polarized relay PR are energized in multiple over a polarized track circuit provided for section 3T. Referring now to Fig. 2, the track rails of section 3T are supplied with current of normal polarity from battery All when relay AHR is released and its back contacts I 4 and I! are closed, and with current of the opposite or reverse polarity from battery 40 when relay AHR is picked up to close its front contacts I8 and I9. Relays TSR and PR are normally connected with the rails of section 3T in multiple over a circuit path extending from rail I through front contact M and the winding of relay TSR to rail Ia, or through front contact 42 of relay TSR, the winding of relay PR and front contact 43 of relay TSR to rail la, It follows, therefore, that when section 3T i vacant, relays TSR and PR are supplied with current of normal or reverse polarity according as relay AHR is released or picked up, respectively. When the polar armature of relay PR is in its caution'or left-hand position, as viewed in the drawings, relay TSR is then connected in circuit with the track rails over an alternate or pick-up circuit path extending from rail 1 through polar contact 44 of relay PR and the winding of relay TSR to the otherv rail la. Also, relay TSR when released completes an alternate circuit extending from one terminal of a suitable source of current, such as a battery 45, through back contact 46 of relay TSR, the winding of relay PR and back contact 4'! of relay TSR to the other terminal of battery 45. The current supplied over this last traced circuit is of normal polarity and hence it will cause relay PR to shift its polar armature to its caution position each time relay TSR releases.

Relay TSR is provided with a slow releasing repeater relay TSPR energized over an obvious circuit including front contact 39 of relay TSR.

Relays TSPR and PR cooperate in controlling signal 3S in a manner substantially corresponding to the control of that signal by relays SR and PR in Fig. l.

The back lock release circuit for energizing lock magnet LM isrepresented in Fig.2 as being completed only at-polar contact 33 of relay PR, and hence it corresponds to the control established by relay PR of Fig. '1 over the back lock circuit represented in Fig. 1.

In the normal condition of the apparatus, as represented in Fig. 2, section 3T i vacant and relay AI-IR is released to cause battery 40 to supply current of normal polarity to the track rails so that relays TSR and PR are both energized by this normal polarity current and the polar armature of relay PR occupies its caution position. Relay TSPR is energized and as a result lamp Y of signal 3S is energized over a circuit extending ffron'i terminal X through front contact 48 of relay TSPR polar contact 3| of relay PR and the filament of lamp'Y of signal 38 to terminal C. 7

When relay AER is picked up, its front contacts l8 and I9 will close to reverse the polarity of current supplied from battery 40 to relays TSR and PR through the track rails, and relay "TSR of course will release since the direction of flux in the relay reverses. When relay TSR releases. its back contacts 46 and 4'! will close TSR With the track rails over the pick-up circuit path including polar contact 44 of relay PR. As a result, relay TSR will. pick up in response to current of reverse polarity received from the track rails and front'contact 4| will close to complete its stick circuit path while front contacts 42 and 43 will close to connect the Winding of relay PR in multiple with the Winding of relay TSR, Whereupon'relay PR will shift its polar armature to its clear position. Signal 3S accordingly will be caused to display its clear aspect over a circuit extending from terminal B through front contact 48 of relay TSPR. polar contact 32 of relay PR and the filament of lamp G of signal ES to terminal C. It should be noted that the slow releasing features of relay TSPR function to hold front contact 48 of that relay closed during the short interval that relay TSR is released due to the reversal of current polarity in its winding, and as a result there will be no momentary display of the red aspect when the polarity of current in the track circuit is reversed.

If, new a train enters section 3T. relays TSH and PR will be shunted and relay TSR will release to close its back contacts 45 and 41 and supply current of normal polarity'from battery 45 to relay PR. Relay PR accordingly will shift its polar armature back to its caution position, thereby closing its polar contact 33 to prepare the back lock release circuit to enable the operator to release the back locking and restore the signal lever ISL to its normal position after the train passes signal In addition, relay TSPR is deenergized and will release at the end of its slow release interval to'close its back contact 49 and complete an obvious energizing circuit for lamp R of signal 3S.

When the train vacates section 3T, current of normal polarity will be supplied to the track rails since relay AHR will be released at this time, and

relay 'I'SR will become energized over its pickup circuit including polarcontact 44 of relay PR. Relay 'TSR accordingly will pick up and close its front contact 4| to complete its stick circuit path and its front contacts 42 and 43 to connect the winding of relay PR in multiple with the winding of relay TSR. In addition, relay TSPR will pick up and lamp Y of signal 3S will become energized over its previously traced circuit so that the apparatus of Fig. 2'will be restored to its normal condition if relay PR operates its polar armature in the proper manner.

If, however, the polar armature of relay PR should stick in its clear position and relay PR should fail to operate the polar armature from its clear to its caution position when section3T is entered, the apparatus functions to prevent a release of the back locking and the display of a false clear signal by the distant signal 3S. That is to say, if the polar armature of relay PR should stick in its clear position, then after the'train enters section 3T and subsequently passes signal IS, the back lock release circuit will be held open at polar contact 33 of relay PR if the operator attempts to restore lever ISL to its normal position. In addition, when section 31 is vacated, signal 38 will be held at its stop position since with polar contact 44 of relay PR held open, the pick-up circuit path ofrelay TSR cannotbe completed and as a result relay TSPR is held released to maintain the energizing circuit of lamp R of signal 3S. 'The apparatus of Fig. 2 accordingly functions in much the same manner as the apparatus of Fig. 1 to prevent the display of a false clear aspect and the release of the back locking of signal lever ISL if the polarized control relay PR of the distant signal 38 fails to operate its polar armature in the proper manner.

Fig. 3 illustrates another modification of the apparatus represented in Fig. 1, wherein a polarized track relay PTR constantly connected-with the rails of section 3T cooperates with stick relay SR in the control of signal 38 to prevent a false clear signal from being displayed if the polar armature of relay PTR sticks in its clear position and the relay fails to operate that armature in the proper manner. 1

Referring now to Fig. 3, relay SR is normally energized over a stick circuit extending from terminal X through front contact 59 of relay SR, front contact 5| of relay P'I'R and the winding of relay SR to terminal C, and is provided'with a pick-up circuit including polar contact 52 of re lay PTR and front contact 5| of relay P'IR. When relay SR is picked up, signal 35 will display its clear aspect when the polar armature of relay PI'R is in its clear position to close polar contact 53 and complete a circuit extending from terminal X through front contact 54 of relay SR, polar contact 53 of relay PTR and the filament of lamp G of signal 35 to terminal C; and the signal will display its caution aspect when relay SR is picked up and the polar armature of relay PIR is in its caution position to close polar contact 55 and complete a circuit extending from terminal X through front contact '54 of relay SR, polar contact 55 of relay PTR and the filament of lamp Y of signal 38 to terminal C. When relay SR is released, signal 3S will display its caution aspect when relay PTR is picked up to close its front contact 55 and complete a circuit extending from terminal X through back contact 51 of relay SR,- frontcontact 56 of relay PTR and the filament of lamp Y of signal ES to terminal C; and the signal will display its stop aspect .whenever bothrelaysSR and PTR are released to complete a circuit extending from terminal X through back contact of relay SR,.back contact 58 of relay PTR and the filament of lamp R of signal'3S to terminalC. V

The back. lock release circuit for energizing lock magnet, LM of Fig. 3 is connected with terminal Xat either polar contact 59 of relay PTR or back contact 6|! of relay SR. V

'In the normal condition of the apparatus of Fig. 3, as represented in the drawings, relay AHR is released so that current of normal-polarity is supplied: from battery 40 through the track rails to relay PTR and causes that relay to close its front contacts and operate its polar armature to its caution position. Relay SR is held energized over its stick circuit including its own front contact 50 and front contact 5| of relay PTR, while the pick-up circuit of relay SR alsois completed at polar contact 52 of relay PTR. Signal 38 is caused to display its caution aspect since lamp Y is energized over its previously traced circuit including front contact 54 of relay SR and polar contact 55 of relay PTR.

When relay AHR is picked up, the polarity of current Isupplied tothe track rails is reversed so that relay PTR will shift its polar armature to itsclear'position, and as a result the pick-up circuit of. relay SR willbe open at polar contact 52 and the energizing circuit of lamp G 'of signal 3S will be closed at polar contact 53. I During the reversal of current in relay PTR, its front contacts will of course open to open the stick circuit of relay SR at front contact 5|, butrelay SR is slow releasing and holds its front contact 50 closed until front contact 5| of relay PTR again closes in response to the energization of that relay by current of the reverse polarity, so that relay SR will be maintained energized over its stick circuit after relay PTR shifts its polar armature to its clear position. J

When a train enters section 3T of Fig. 3, relay PTR will be shunted and will release to open the stick circuit of relay AR at front contact 5|, whereupon that relay in turn releases to close its back contact 51 and thereby complete the previously traced energizing circuit for lamp R of signal 3S. In addition, contact B ll of relay SR closes to prepare the back lock release circuit of lock magnet LM, so that after the train passes signal IS and relay AHR is caused to release in the manner made clear in the description of the operation of the apparatus of Fig. l, the operator may restore lever ISL-to its full normal position.

When the train vacates section 3T, current of normal polarity will be supplied from battery 40 throughthe track rails to relay PTR to cause that relay to shift its polar armature back to its caution position, whereupon relay SR will be picked up over its pick-up circuit including polar contact V 52 and front contact 5| of relay PTR. When relay SR picksup, signal 38 will be caused to display its caution aspect due to the energization of lamp Y of signal 38 over its previously tracedcircuit including front contact 54 of relay SR. and polar contact 55 of relay PTR.

If, however, the polar armature of relay PTR should stick in its clear position and that relay fails to operate its polar armature to its caution position when supplied with current of normal polaritylafter the section 3T becomes vacant, then this improper. operation of the polar arma ture of relay PTR willbe detected since the pickup circuit of relay SR will be held open at polar contact 52 of relayPTR. Relay SR accordingly will remain released even though the front contacts of relay PTR might become closed due to the energization of that relay by current of normal polarity. In such an event, signal 35 will be caused to display its caution aspect over a circuit extending fromterminal X through back contact 51 of relay SR,'front contact 56 of relay PTR and the filament of lamp Y of signal 38. It will be noted that this aspect will be proper under the particular conditions specified, that is, with section'3T vacant and signal IS at stop. The distant signal 38 will be maintained at this caution aspect should relay AHR be picked up in clearing signal IS since although the reverse polarity current supplied to relay PTR from battery 40 through front contacts |8 and IQ of relay AHR andthe track rails will be in agreement with the position of the polar armature of relay PTR, the pick-up circuit of'relay SR will still be open at polar contact 52 of relay PTR so that relay SR will still be maintained released and will keep its back contact 51 closed to maintain the previously traced circuit of lamp Y. It follows that'the apparatus represented in Fig. 3 incorpor'ates a stick relay SR arranged to prevent the display of afalse clear signal in the event that the polarized control relay PTR employed in the control of the distant signal 38 fails to operate its polar armature properly. This provides a check on the operation of the polarized relay PTR to prevent a false clear failure of signal 38, even though the failure of the relay is not detected by the back lock release circuit which includes back contact 60' of relay SR and hence is prepared whenever relay SR is released.

From the foregoing, it is readily apparent that the display of a false clear aspect by the distant signal 3S is prevented by each of the embodiments of myinvention represented in Figs. 1, 2 and 3 should the polarized relay employed in the control of the distant signal fail to operate its polar armature in the proper manner; and that each of the embodiments represented in Figs. 1, la and 2 of the drawings functions to prevent the release of the back looking on the home signal lever if the polar armature of the polarized relay fails to operate properly.

Although I have herein shown and described only a few forms of traffic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made th erein'within the scope of the appended claims without departing from the spirit and scope of 'my invention.

Having thus described my invention, what I claim is:

1. In combination with a section of railway track provided with a signal for governing traffic in said section, a polarized relay, means governed by traffic in said section and effective when said section is vacant for supplying current of one relative polarity or the other to said polarized. relay for operating the polar armature thereof to the one position or another respectively. a stick relay normally energized over a stick circuit ncluding its own front contact and so governed by trafiic conditions in said section as to be completed only when said section is vacant, a pick-u circuit for said stick relay including a polar contact'of said polarized relay closed in said one position of its polar armature and governed by traffic conditions in said section to be completed only when said section is vacant, a clear circuit for said' signal governed by a front contact of said stick relay and a polar contact of said polarized relay closed in said other position of its polar armature. a caution circuit for said signal governed by a front contact of said stick relay and a polar contact of said polarized relay closed in said one position of its polar armature, and a stop circuit for said signal completed when said slick relay is released.

2. In a railway interlocking system, an approach section, a first signal governing traffic in said approach section, another signal governing traflic in advance of said approach section, a control lever operable from a normal to an operated position for controlling said other signal, a lock magnet for said lever effective when deenergized to prevent movement of said lever from said operated position into said normal position, a polarized relay, means governed by trafiic in said approach section effective when that section is vacant for supplying current of normal or reverse polarity to said polarized relay for operating the polar armature thereof to one position or another respectively, a stick relay normally energized over a, stick circuit including its own front contact and governed by trafilc conditions in said section to be completed only when said section is vacant, a pick-up circuit for said stick relay including a polar contact of said polarized relay closed in said one position of its polar armature and governed by trafilc conditions in said section to be completed only when said section is vacant, a clear circuit for said signal governed b a front contact of said stick relay and a polar contact of said polarized relay closed in said other position of its polar armature, a caution circuit for said signal governed by a front contact of said stick relay and a polar contact of said polarized relay closed in said one position of its polar armature, a stop circuit for said signal completed when said stick relay is released, and an energizing circuit for said lock magnet controlled by said control lever and connected with one terminal of a source of current through a polar contact of said polarized relay closed in said one position of its polar armature.

3. In a railway interlocking system, an approach section, a first signal governing trafiic in said approach section, another signal governing traific in advance of said approach section, a control lever operable from a normal to an operated position for controlling said other signal, a lock magnet for said lever effective when deenergized to prevent movement of said lever from said operated position into said normal position, a polarized relay, means governed by traflic in said approach section effective when that section is vacant for supplying current of normal or reverse polarity to said polarized rela for operat ng the polar armature thereof to one position or another respectively, a stick relay normally energized over a stick circuit including its own front contact and governed by traflic conditions in said tion to be completed only when said sect on s vacant, a pick-up circuit for said stick relay ncluding a polar contact of said polarized relay closed in said one position of its polar armature and governed by traffic conditions in sa d sect on to be completed only When said section is vacant. means controlled by said stick relay and effective when said approach section becomes occupied for supplying current of said normal polarity to said polarized relay, a clear circuit for said signal governed by a front contact of said stick rela and a polar contact of said polarized relay closed in said other position of its polar armature, a cauti n circuit for sa d i nal o e ned by a r n contact of said stick relay and a polar contact of said polarized relay closed in said one position of its polar armature, a stop circuit for said signal completed When said stick relay is released, and an energizing circuit for said lock magnet controlled by said control lever and connected with one terminal of a, source of current through a polar contact of said polarized relay closed in said oneposition of its polar armature.

4:. In combination with a section of railwaytrack provided with a signal for governing traffic in said section, a track circuit including a track relay for said section, a polarized relay, circuit means including a front contact of said track relay for supplying current of normal or reverse polarity to said polarized relay for operating the polar armature thereof to one position or another respectively, a slow releasing rela provided with energizing circuit means completed through a front contact of said track relay and a front contact of said polarized relay, circuit means completed durin the solw release interval of said slow releasing relay and including back contacts of said track relay for supplying current of said normal polarity to said polarized relay, a clear circuit for said signal including a front contact of said slow releasin relay and a polar contact of said polarized relay closed in said other position of its polar armature, a caution circuit for said signal includin a front contact of said slow releasing relay and a polar contact of said polarized relay closed in said one position of its polar armature, and a stop circuit for said signal including a back contact of said slow releasing relay.

5. In combination with a section of railway track, a track circuit for said section includin a track relay, a circuit controlled b said track relay for energizing said polarized relay, means for controlling the relative polarity of current supplied over said circuitto said polarized relay for causing that relay to operate its polar armature to one position or another according as current of one relative polarity or the other is suplied to that relav, a slow releasing relay normally energized over a stick circuit including in series its own front contact and front contacts of said track and polarized control relays, apickup circuit for said slow releasing relay including in series front contacts of said track and polarized control relays and a polar contact closed in said one position of the polar armature of said olarized control relay, circuit means including in. series a front contact of sa d slow releasing relay and back contacts of said track relay for supply ng current of said one relative polarity to said polarized control relay, and a control circuit connected with one terminal of a source of current only through a polar contact of said polarized. control relay closed in said one position of the polar armature of said polarized control relay.

6. In combination. with a section of railway track, a signal governing traffic in sa d section. a track circuit for said section including a track relay. a circuit controlled by said track relay for energizing sa d polarized relay, means for con trolling the relative polarity of current supplied over said circuit to said polarized relay for causing that relay to operate its polar armature to one position or another according as current of one relative polarity or the other is supplied to that relay, a slow releasing relay normall en ergized over a stick circuit including in series its own front contact and front contacts of said track and polarized control relays, a pick-up circuit for said slow releasing relay including in series front contacts of said track and polarized control relays and a polar contact closed in said one position of the polar armature of said polarized control relay, circuit means including in series a front contact of said slow releasing relay and back contacts of said track relay for supplying current of said one relative polarity to said polarized control relay, a control circuitconnected with one terminal of a source of current only through a polar contact of said polarized con trol relay closed in said one position of the polar armature of said polarized control relay, and circuit means including a back contact of said slow releasing relay for causing said signal to display stop and including a front contact of said slow releasing relay for causing said signal to display caution or clear according as the polar armature of said polarized control rela is in its said one or said other position respectively.

7. In combination with a section of railway track, a track circuit including a track relay for said section, a signal governing traflic in said section, a polarized control relay, a circuit controlled by said track relay for energizing said polarized control relay, means for controllingthe relative polarity of current supplied over said circuit to said polarized control relay for causing said'-polarized control relay to operate its polar armature to one position or another according as current of one relative polarity or the other is supplied to that relay, a slow releasing relay normally energized over a stick circuit including its own front contact and front contacts of said track and polarized control relays,'a pick-up circuit for said slow releasing relay including front contacts of said track and polarized control relay and a polar contact closed in said one position of the polar armature of said polarized control relay, and circuit means including a back contact of said slow releasing relay for conditioning said signal to display stop'and including a front contact of said slow releasing relay for conditioning said signal to displaycaution or clear according as the armature of said polarized relay occupies its said one or said other position'respectively.

8. In combination with a section of railway track, a track circuit including a track relay for said section, a polarized control relay, a circuit controlled by said track relay for energizing said polarized control relay, means for controlling the polarity of current supplied to said circuit for causing said polarized control relay to operate its polar armatureto one position or another according as current of one relative polarity or another is supplied to the relay, a slow releasing relay energized over a circuit including a front contact of said track relay and a front contact of said polarized control relay, a circuit including a front contact of said slow releasing relay and back contacts of said track relay for supplying current of said one relative polarity to said polarized control relay, and a control circuit connected to a sourceof current only at a polar contact of said polarized control relay closed in the said one position of its polar armature.

9. In a railway interlocking system, an approach section, a first signal governing traffic in said section, another signal governing traffic in advance of said section, a control lever operable from a normal to an operated position for controlling said other signal, a lock magnet for said lever eifective when deenergized to prevent movement of said lever from said operated position into said normal position, a polarized signallcontrol relay, a polarized circuit controlled by said control lever and by trafiic in said approach section for energizing said polarized control relay with current of one relative polarity or the other to cause that relay to operate its polar armature to one or another position respectively, a, stick relay normally energized over a stick circuit including its own front contact and governed by trafiic in said section, a pick-up circuit for said stick relay governed by trafiic in said section and including a polar contact closed in said one position of the polar armature of said polarized control relay, means controlled by said stick relay and effective when said approach section first becomes occupied by a train for supplying current of said one relative polarity to said polarized control relay, means controlled by said stick and polarized control relays for governing said first signal, and an energizing circuit for said lock magnet controlled by said control lever and connected with one terminal of a source of current only through a polar contact closed in said one position of the polar armature of said polarized control relay.

10. In combination with a section of railway track provided with a signal for governing traffice in said section, a polarized relay having a polar armature caused to operate to one position or another according as current of one relative polarity or the other is supplied to the relay, means for supplying current of one relative polarity or the other to the rails of said section at the end remote from said signal, a neutral track relay normally connected over its own front contact in circuit withthe rails at the section end adjacent to said signal, means including a front contact of' said track relay for connecting said polarized relay with said section rails in multiple with said track relay, means including back contacts of said track relay for supplying current of said one relative polarity to said polarized relay, an alternate circuit including a polar contact of said polarized relay closed in said one position of its polar armature for connecting said track relay in circuit with the track rails, a clear circuit for said signal including a polar contact of said polarized relay closed in said other position of its polar armature and governed by said track relay, a caution circuit for said signal including a polar contact of said polarized relay closed in said one position of its polar armature and governed by said track relay, and a stop circuit for said signal governed by said track relay and rendered effective when said track relay is released.

11. In combination with a section of railway track provided with a signal for governing traffic in said section, a polarized relay having a polar armature caused to operate to one position or another according as current of one relative polarity or another is supplied to said relay, means for supplying current of one relative polarity or the other to the rails of said section at the end remote from said signal, a neutral track relay normally connected over its, own front contact in circuit with the rails at the section end adjacent to said signal, means including a front contact of said track relay for connecting said polarized relay with said section rails in multiple with said track relay, means including back contacts of said track relay for supplying current of said one relative polarity to said polarized relay, an alternate circuit including a polar contact of said polarized relay closed in said one position of its polar armature for connecting said track relay in circuit with the track rails, a clear circuit for said signal including a polar contact of said polarized relay closed in said other position of its polar armature and governed by said track relay, a caution circuit for said signal including a polar contact of said polarized relay closed in said one position of its polar armature and governed by said track relay, a stop circuit for said signal governed by said track relay and rendered effective when said track relay is released, and a lock circuit for apparatus in advance of said section governed by a circuit connected with one terminal of a source of current only at a polar contact of said polarized relay closed in said one position of its polar armature.

12. In combination, a section of railway track, a polarized relay connected with the rails of said section, means for controlling the relative polarity of current supplied to said polarized relay over the track rails of said section for causing that relay to operate its polar armature to one position or another according as current of one relative polarity or the other is supplied to the relay, a slow releasing stick relay normally energized over a stick circuit including in series its own front contact and a front contact of said polarized relay, a pick-up circuit for said stick relay including a front contact of said polarized 'relay and a polar contact of said polarized relay closed in the said one position of the polar armature of said polarized relay, and circuit means for controlling said signal including a back contact of said stick relay for causing said signal to display stop and including a front contact of said stick relay for causing said signal to display caution or clear according as the polar armature of said polarized relay occupies its said HENRY S. YOUNG. 

